SEMATEXT-LOGGER

With sematext-logger, log events can be send to Sematext and output to the console at the same time.

Install

go get github.com/Ephram84/sematext-logger

Usage

First create a new logger:

logger := sematextlogger.NewLogger(appToken, service)

Parameter:

• appToken (string, required): Is the token of your Logsene app. You will find it on sematext website.
• service (string, required): Typ is a logical division of events and can be anything. For example, for syslog messages typ would be called "syslog". But also the name of your app would be possible. Default is syslog.

If you have an enviroment variable that contains a url with an appToken, e.g., https://logsene-receiver.sematext.com/fzr64ktn-...., you can use:

logger := sematextlogger.InitLogger(envVarName, service)

Send message

Logger can now be used to call different methods that specify different severities. For example, the following code

logger.Error("any ID", "An error has occurred", "-", errors.New("Example error").Error())

produces this output {"request_id":"65CMp4TVdaZbJUCAJQGLopWsZUPhaKlp","time":"2018-04-07T10:29:15+02:00","loglevel":"ERROR","service":"test","file":"testAPI.go","line":"47","message":"An error has occurred - Example error"}

Please note that "any ID" is any alphanumeric string, e.g. the RequestID to easily find the message at Sematext. The remaining parameters form the message.

Using Echo

If you want to implement a REST API with Echo, process following steps.

1. Import sematext:

import(
    ...
    sematextlogger "github.com/Ephram84/sematext-logger"
    ...
)

2. Define a custom context:

type TestContext struct {
	echo.Context
	Sematextlogger *sematextlogger.Logger
}

3. Create a new sematext logger and a middleware to extend default context:

  logger := sematextlogger.NewLogger(os.Getenv("LOGGING_URL"), "test")

  router := echo.New()
  router.HideBanner = true

  router.Use(logger.EchoMiddlwareLogger()) // Replaces Echo's default logger with the difference that the output is also sent to Sematext.
  router.Use(middleware.RequestID())  // Automatically generates a request ID.
  router.Use(func(h echo.HandlerFunc) echo.HandlerFunc {
    return func(c echo.Context) error {
      tcontext := &TestContext{c, logger}
      return h(tcontext)
    }
  })

4. Send a message within a HandlerFunc:

context := c.(*TestContext)
...
context.Sematextlogger.Error(context.Response().Header().Get(echo.HeaderXRequestID), "An error has occurred", " - ", errors.New("Example error").Error())
return context.JSON(http.StatusConflict, "An error has occurred")